Lindisfarne Gospels - http://en.wikipedia.org/wiki/Lindisfarne_Gospels
The Lindisfarne Gospels is an illuminated Latin manuscript of the gospels of Matthew, Mark, Luke and is now kept in the British Library. The manuscript was produced on Lindisfarne in Northumbria in the late 7th century or early 8th century, and is generally regarded as the finest example of this period's religious art; a hybrid Celtic style commonly known as Insular art.
The Gospels are richly illustrated in exceptional detail, and were originally encased in a fine leather binding covered with jewels and precious metal. During the Viking raids on Lindisfarne, however, this cover was lost.

Chevaux De Frise - http://en.wikipedia.org/wiki/Cheval_de_frise
The cheval de frise was a Medieval defensive obstacle consisting of a portable frame (sometimes just a simple log) covered with many long iron or wooden spikes or even actual spears.
The term also came to be used for any spiked obstacle, such as the lines of angled stones constructed as a defensive perimeter around the prehistoric fort of Dun Aengus on Inishmore.

Lebor Gabala Erenn - http://en.wikipedia.org/wiki/Lebor_Gababala_Erenn
Lebor Gabála Érenn (The Book of the Invasions) is the Middle Irish title of a collection of poems and narratives recounting the mythical origins and history of the Irish race from the creation of the world down to the Middle Ages. An important record of the folkloric history of Ireland, it was compiled and edited by an anonymous scholar in the 11th century. The work can be divided into ten "books" which includes accounts of the early history of civilisation (6th century BC) including Fomorians, Tuatha De Danann and Fir Bolg. It also chronicles the the battles of Mag Tuired and Balor's "Evil Eye" weapon. It is now thought that ancient knowledge was transmitted orally from generation to generation by the druids of pre-literate Ireland. Prominent historians now believe some of LGE's traditions "archaeologically plausible".
The most famous copy is contained in The Book of Leinster (Irish Lebor Laignech), a medieval Irish manuscript compiled ca. 1160 and now kept in Trinity College,

Ogham Script - http://en.wikipedia.org/wiki/Ogham
Ogham is an Early Medieval alphabet used primarily to write the Old Irish language. The evidence points to a creation date for Ogham sometime around the 3rd century. There are several theories concerning the origins. One theory put forward by the noted Ogham scholar R.A.S. Macalister suggests that it was first invented in Cisalpine Gaul around 600 B.C. by Gaulish druids as a secret system of hand signals, and was inspired by a form of the Greek alphabet. One reason for considering this theory based on hand signals, is that each character comprises between one and five strokes. According to the 11th century Lebor Gabála Érenn, the 14th century Auraicept na n-Éces, and other medieval works, Ogham was first invented soon after the fall of the Tower of Babel along with the Gaelic language, by the legendary Scythian king, Fenius Farsa. The Book of Ballymote (1390), explains the use of Ogham script in its various forms.
As well as its use for monumental inscriptions, the evidence from early Irish sagas and legends indicates that Ogham was used for short messages on wood or metal, either to relay messages or warnings or to denote ownership. Some of these messages seem to have been cryptic in nature and some were also for magical purposes.

Book of Ballymote - http://en.wikipedia.org/wiki/Book_of_Ballymote
The Book of Ballymote, named after the parish of Ballymote in County Sligo, Ireland. It was written in 1390 by two scribes on commission by Tonnaltagh McDonagh, in whose clan the manuscript remained until 1522. In 1620 it was given to Trinity College, Dublin, but was subsequently stolen from their library. Only to be returned to the Royal Irish Academy upon its foundation in 1785 by Chevalier O'Gorman, who allegedly purchased it from a millwright's widow for 20 pounds. The book is a compilation of much older works, mostly loose manuscripts and valuable documents handed down from antiquity that came into possession of McDonagh. It contains treatises on the history of the Jewish people, St. Patrick and his household, Cormac's instructions to a king and a physical and geological survey of Ireland. Part of the work is devoted to the lives of Finn and Brian Boru, while the Book of Rights, which was translated and edited in 1847, is taken entirely from the Book of Ballymote.
Of unique historical importance it also contains instruction and examples of the sacred ancient Ogham writing and language.

Book of Kells - http://en.wikipedia.org/wiki/Book_of_Kells
The Book of Kells (also called the Book of Columba) is an illuminated Gospel in Latin, containing the four Gospels of the New Testament together with additional texts and tables. It was created by Celtic monks around 800AD. The text of the Gospels are mainly from the Vulgate, although sections are from an earlier version of the Bible known as the Vetus Latina. It is stunning example of monastic calligraphy and is probably the pinnacle of Insular illumination; it is widely accepted as Ireland's finest national treasure.
The illustrations and ornamentation of the Book of Kells surpass that of other Insular Gospel books in extravagance and complexity. The decoration combines traditional Christian iconography with the ornate swirling motifs typical of Insular art. It takes its name from the Abbey of Kells that was its home for centuries.
The Abbey was plundered by Vikings many times in the 10th century, but the book survived. The earliest historical reference to the book's presence at Kells, can be found in a 1007 entry in the Annals of Ulster. This entry records that "the great Gospel of Columkille, the chief relic of the Western World, was wickedly stolen during the night from the western sacristy of the great stone church at Cenannas". It was recovered a few months later without it's gold and bejewelled cover from "under a sod".
The force of ripping the manuscript free from its cover may account for the folios missing from the beginning and end of the Book of Kells, or they might have been removed for other reasons.
The decorations of the Book of Kells can be stunningly complex and may only fully appreciated under magnification.
Today, it is on permanent display at the Trinity College Library, Dublin.

Gerald of Wales - http://en.wikipedia.org/wiki/Gerald_of_Wales
Gerald of Wales (c. 1146 – c. 1223), was a medieval clergyman and chronicler of his times. In his book Topographia Hibernica (Topography of Ireland), he describes seeing a great Gospel Book in Kildare which many have since assumed was the Book of Kells. The description certainly matches Kells:
"This book contains the harmony of the Four Evangelists according to Jerome, where for almost every page there are different designs, distinguished by varied colours. Here you may see the face of majesty, divinely drawn, here the mystic symbols of the Evangelists, each with wings, now six, now four, now two; here the eagle, there the calf, here the man and there the lion, and other forms almost infinite. Look at them superficially with the ordinary glance, and you would think it is an erasure, and not tracery. Fine craftsmanship is all about you, but you might not notice it. Look more keenly at it and you will penetrate to the very shrine of art. You will make out intricacies, so delicate and so subtle, so full of knots and links, with colours so fresh and vivid, that you might say that all this were the work of an angel, and not of a man."
Since Gerald states to have seen this book in Kildare, it must have been another, now lost, book equal in quality to the Book of Kells. He makes no reference to a missing cover or any other damage, so we can reasonably assume that this copy still had it's lavishly decorated cover intact.

The Book of Revelation - http://en.wikipedia.org/wiki/Book_of_Revelation
The Book of the Revelation to John, often referred to as the Book of Revelation or simply Revelation, is the last in the collection of documents which constitute the New Testament. It is also known as the Apocalypse of John or simply the Apocalypse. Apocalypse: a prophetic revelation concerning a cataclysm in which the forces of good permanently triumph over the forces of evil. It describes a prophecy of the final battle between good and evil on the plains of Armagedon and the end of the world as we know it. It is also acts as a symbolic way of ending the Bible scriptures: starting with the creation of the world in The Book of Genesis at the start of The Old Testament and closing with the end of the world in The Book of Revelation at the end of The New Testament.
The instruments of destruction are depicted as four riders mounted on white, red, black, and pale horses symbolising pestilence, war, famine, and death, respectively. The Christian apocalyptic vision is that the four horsemen invoke a divine apocalypse upon the Earth as harbingers of the Last Judgment of God.
Revelation (The Mark of The Beast) 13:16-18:
"16 And he causeth all, both small and great, rich and poor, free and bond, to receive a mark in their right hand, or in their foreheads:
17 and that no man might buy or sell, save he that had the mark, or the name of the beast, or the number of his name.
18 Here is wisdom. Let him that hath understanding count the number of the beast: for it is the number of a man; and his number is Six hundred ten and six."

The Number of The Beast
616 ("six hundred and sixteen", or "six sixteen" in American English) is now believed by scholars to have been the original Number of the Beast in the Book of Revelation in the Christian Bible. Some early versions of the Book of Revelation deceptively gave a different number, and as a result 666 has been widely accepted as the original value. In 2005, however, a fragment of papyrus 115 came to light, containing the earliest known version of that part of the Book of Revelation discussing the Number of the Beast. Papyrus 115 is a fragmented manuscript of the New Testament written in Greek on papyrus. It consists of 12 fragments of a codex containing parts of the Book of Revelation. Grenfell and Hunt discovered the papyrus at Oxyrhynchus, Egypt and correctly dated it to the third century, ca. 225-275AD. However it was not deciphered and published until the end of the twentieth century, and is currently housed at the Ashmolean Museum. It gave the correct number as 616, confirming that this was the true Number of The Beast. An eminent expert in this field, Dr. Ellen Aitken said: "Scholars have argued for a long time over this, and it now seems that 616 was the original number of the beast. It's probably about 100 years before any other version."